“I appreciate your effort” is a phrase whose function is to veil the active negation of one’s success. It really means “I judge that you failed”. That’s why seeking appreciation is dangerously close to seeking “failure” by being subjugated to others’ judgement.
When I distinguish real engagement from symbolic engagement in “effort”,  I distinguish the reality of sacrifice and commitment from the symbolization of success. In the example sentence above, the distinction between the subject of the statement and the subject of the enunciation is crucial: The word “effort” (1) explicitly emphasizes the sacrifice in the person’s commitment or engagement, (2) implicitly posits his/her engagement as “mere sacrifice” (or simply “waste”) that has been in vain, that has led to nothing.
The word “struggle” functions similarly as in the phrase “I respect your struggle”. “Struggling” emphasizes the sacrificial aspect of commitment, but it often also implies “struggling in vain”. The Marxist notion of “class struggle” embodies this ambiguity: It signifies a great commitment and fidelity to a political cause, but it also signifies a constant condemnation to failure.
These two aspects, success & sacrifice (symbolic & real) correspond to energy & entropy respectively . Slavoj Žižek’s philosophy immerses in the sacrificial aspect of entropy; that’s why he often emphasizes “the void of the Real” and that’s why he declares “There is nothing, basically, I mean it quite literally” in the documentary Žižek! (2005) . For Žižek, “the act” is a negative gesture which does not concern itself with seeking success. A proper act changes the coordinates of the big Other and shifts the very definition of “success”, it renders possible what previously seemed impossible. All of this is true, but we nonetheless must also state what “success” means symbolically, if we are to succeed in evading the judgement of the Other.
All success is symbolic and it’s always a success of the repression of sacrifice. We can detect this in the example sentences above. “I appreciate your effort” seeks to repress the subject’s sacrifice under the symbolic “appreciation” of the sovereign enunciator. “I respect your struggle” functions in a similar way. If we let others repress and symbolize our sacrifice by their “appreciation” and “respect”, we become symbolically subjugated to their power, and we ourselves become sacrificed for the sovereignty of their symbolic judgement.
“Sacrifice of sacrifice”, interpreted in this way, points to the right direction. Our sacrifice for the sovereignty of the Other should be negated for the sake of our own sacrifice for ourselves. We ourselves should wield the symbolic power of repression, the power to name our own success by repressing our sacrifice. This is what necessitates us to reclaim the words “effort” and “struggle” for our ends. We must learn to “appreciate” and “respect” ourselves without seeking it from others. We must not display and exhibit our sacrifice for others to repress, symbolize and feed their sovereignty. To earn and appropriate our success and sovereignty, we must learn to symbolize and repress our own sacrifice by ourselves. This is what sacrificing the sacrifice means. Repression is crucial for success because it is ultimately the power of repression that makes a “sacrifice” out of the pure waste of the real.
 See “Love is evil”